systemctl: support remote and privileged systemctl access via SSH and pkexec

This adds support for executing systemctl operations remotely or as
privileged user while still running systemctl itself unprivileged and
locally.

This currently requires a D-Bus patch to work properly.

https://bugs.freedesktop.org/show_bug.cgi?id=35230

1 files changed, 52 insertions, 16 deletions

diff --git a/src/systemctl.c b/src/systemctl.c
index 5b205fec56..b8af654e09 100644
--- a/src/systemctl.c
+++ b/src/systemctl.c
@@ -108,6 +108,12 @@ static enum dot {
         DOT_ORDER,
         DOT_REQUIRE
 } arg_dot = DOT_ALL;
+static enum transport {
+        TRANSPORT_NORMAL,
+        TRANSPORT_SSH,
+        TRANSPORT_POLKIT
+} arg_transport = TRANSPORT_NORMAL;
+static const char *arg_host = NULL;
 
 static bool private_bus = false;
 
@@ -2061,12 +2067,14 @@ static void print_status_info(UnitStatusInfo *i) {
 
                 printf("\t  CGroup: %s\n", i->default_control_group);
 
-                if ((c = columns()) > 18)
-                        c -= 18;
-                else
-                        c = 0;
+                if (arg_transport != TRANSPORT_SSH) {
+                        if ((c = columns()) > 18)
+                                c -= 18;
+                        else
+                                c = 0;
 
-                show_cgroup_by_path(i->default_control_group, "\t\t  ", c);
+                        show_cgroup_by_path(i->default_control_group, "\t\t  ", c);
+                }
         }
 
         if (i->need_daemon_reload)
@@ -4290,22 +4298,25 @@ static int systemctl_help(void) {
                "                      pending\n"
                "     --ignore-dependencies\n"
                "                      When queueing a new job, ignore all its dependencies\n"
+               "     --kill-mode=MODE How to send signal\n"
+               "     --kill-who=WHO   Who to send signal to\n"
+               "  -s --signal=SIGNAL  Which signal to send\n"
+               "  -H --host=[user@]host\n"
+               "                      Show information for remote host\n"
+               "  -P --privileged     Acquire privileges before execution\n"
                "  -q --quiet          Suppress output\n"
                "     --no-block       Do not wait until operation finished\n"
-               "     --no-pager       Do not pipe output into a pager.\n"
-               "     --system         Connect to system manager\n"
-               "     --user           Connect to user service manager\n"
-               "     --order          When generating graph for dot, show only order\n"
-               "     --require        When generating graph for dot, show only requirement\n"
                "     --no-wall        Don't send wall message before halt/power-off/reboot\n"
-               "     --global         Enable/disable unit files globally\n"
                "     --no-reload      When enabling/disabling unit files, don't reload daemon\n"
                "                      configuration\n"
+               "     --no-pager       Do not pipe output into a pager.\n"
                "     --no-ask-password\n"
                "                      Do not ask for system passwords\n"
-               "     --kill-mode=MODE How to send signal\n"
-               "     --kill-who=WHO   Who to send signal to\n"
-               "  -s --signal=SIGNAL  Which signal to send\n"
+               "     --order          When generating graph for dot, show only order\n"
+               "     --require        When generating graph for dot, show only requirement\n"
+               "     --system         Connect to system manager\n"
+               "     --user           Connect to user service manager\n"
+               "     --global         Enable/disable unit files globally\n"
                "  -f --force          When enabling unit files, override existing symlinks\n"
                "                      When shutting down, execute action immediately\n"
                "     --defaults       When disabling unit files, remove default symlinks only\n\n"
@@ -4472,6 +4483,8 @@ static int systemctl_parse_argv(int argc, char *argv[]) {
                 { "kill-who",  required_argument, NULL, ARG_KILL_WHO  },
                 { "signal",    required_argument, NULL, 's'           },
                 { "no-ask-password", no_argument, NULL, ARG_NO_ASK_PASSWORD },
+                { "host",      required_argument, NULL, 'H'           },
+                { "privileged",no_argument,       NULL, 'P'           },
                 { NULL,        0,                 NULL, 0             }
         };
 
@@ -4483,7 +4496,7 @@ static int systemctl_parse_argv(int argc, char *argv[]) {
         /* Only when running as systemctl we ask for passwords */
         arg_ask_password = true;
 
-        while ((c = getopt_long(argc, argv, "ht:p:aqfs:", options, NULL)) >= 0) {
+        while ((c = getopt_long(argc, argv, "ht:p:aqfs:H:P", options, NULL)) >= 0) {
 
                 switch (c) {
 
@@ -4605,6 +4618,15 @@ static int systemctl_parse_argv(int argc, char *argv[]) {
                         arg_ask_password = false;
                         break;
 
+                case 'P':
+                        arg_transport = TRANSPORT_POLKIT;
+                        break;
+
+                case 'H':
+                        arg_transport = TRANSPORT_SSH;
+                        arg_host = optarg;
+                        break;
+
                 case '?':
                         return -EINVAL;
 
@@ -4614,6 +4636,11 @@ static int systemctl_parse_argv(int argc, char *argv[]) {
                 }
         }
 
+        if (arg_transport != TRANSPORT_NORMAL && arg_user) {
+                log_error("Cannot access user instance remotely.");
+                return -EINVAL;
+        }
+
         return 1;
 }
 
@@ -5622,7 +5649,16 @@ int main(int argc, char*argv[]) {
                 goto finish;
         }
 
-        bus_connect(arg_user ? DBUS_BUS_SESSION : DBUS_BUS_SYSTEM, &bus, &private_bus, &error);
+        if (arg_transport == TRANSPORT_NORMAL)
+                bus_connect(arg_user ? DBUS_BUS_SESSION : DBUS_BUS_SYSTEM, &bus, &private_bus, &error);
+        else if (arg_transport == TRANSPORT_POLKIT) {
+                bus_connect_system_polkit(&bus, &error);
+                private_bus = false;
+        } else if (arg_transport == TRANSPORT_SSH) {
+                bus_connect_system_ssh(NULL, arg_host, &bus, &error);
+                private_bus = false;
+        } else
+                assert_not_reached("Uh, invalid transport...");
 
         switch (arg_action) {